首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   89688篇
  免费   8991篇
  国内免费   7328篇
耳鼻咽喉   652篇
儿科学   857篇
妇产科学   985篇
基础医学   10707篇
口腔科学   1617篇
临床医学   13061篇
内科学   13257篇
皮肤病学   729篇
神经病学   5297篇
特种医学   3262篇
外国民族医学   56篇
外科学   8287篇
综合类   15347篇
现状与发展   22篇
一般理论   13篇
预防医学   5755篇
眼科学   2946篇
药学   9289篇
  102篇
中国医学   5811篇
肿瘤学   7955篇
  2024年   297篇
  2023年   1519篇
  2022年   4282篇
  2021年   5149篇
  2020年   3912篇
  2019年   3207篇
  2018年   3428篇
  2017年   2875篇
  2016年   2825篇
  2015年   4295篇
  2014年   5284篇
  2013年   4478篇
  2012年   6566篇
  2011年   7606篇
  2010年   4590篇
  2009年   3600篇
  2008年   4591篇
  2007年   4490篇
  2006年   4627篇
  2005年   4666篇
  2004年   2738篇
  2003年   2668篇
  2002年   2223篇
  2001年   1945篇
  2000年   2062篇
  1999年   2165篇
  1998年   1475篇
  1997年   1394篇
  1996年   1128篇
  1995年   1045篇
  1994年   867篇
  1993年   566篇
  1992年   607篇
  1991年   516篇
  1990年   477篇
  1989年   443篇
  1988年   371篇
  1987年   297篇
  1986年   240篇
  1985年   192篇
  1984年   90篇
  1983年   53篇
  1982年   48篇
  1981年   40篇
  1980年   34篇
  1979年   23篇
  1978年   3篇
  1977年   7篇
  1975年   1篇
  1964年   1篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
971.
We aim to evaluate the evolution differences in the incidence and case fatality rate (CFR) of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Delta and Omicron variants. The average incidence and CFRs were described between different countries. A gamma generalized linear mixed model (GLMM) was used to compare the CFRs of Delta and Omicron variants based on vaccination coverage. Totally, 50 countries were included for analyses. The incidence of coronavirus disease 2019 (COVID-19) ranged from 0.16/100,000 to 82.95/100,000 during the Delta period and 0.03/100,000 to 440.88/100,000 during the Omicron period. The median CFRs were 8.56 (interquartile range [IQR]: 4.76–18.39) during the Delta period and 3.04 (IQR: 1.87–7.48) during the Omicron period, respectively. A total of 47 out of 50 countries showed decreased CFRs of the Omicron variant with the rate ratio ranging from 0.02 (95% confidence interval [CI]: 0.01–0.03) (in Cambodia) to 0.97 (95% CI: 0.87–1.08) (in Ireland). Gamma GLMM analysis showed that the decreased CFR was largely a result of the decreased pathogenicity of Omicron besides the increased vaccination coverage. The Omicron variant shows a higher incidence but a lower CFR around the world as a whole, which is mainly a result of the decreased pathogenicity by SARS-CoV-2's mutation, while the vaccination against SARS-CoV-2 still acts as a valuable measure in preventing people from death.  相似文献   
972.
The Omicron variant has become the dominant COVID-19 variant worldwide due to its rapid and cryptic spread. Therefore, successful early warning is of great importance to be able to control epidemics in their early phase, before developing into large outbreaks. COVID-19-related Baidu search index, which reflects human behavior to a certain degree, was used to retrospectively detect the warning signs for Omicron variant outbreaks in China in 2022. The characteristics and effects of warning signs were analyzed in detail. We detected the presence of early warning signs (both high and low thresholds) and found that these occurred 4–7 days earlier than traditional epidemiological surveillance and >20 days earlier than the implementation of the local “lockdown” policy. Compared with the “high threshold” warning, the early warning effect of the “low threshold” is also vital because it indicates a negligence about epidemic prevention and control. However, there is obvious heterogeneity in the optimal threshold for detecting early warning signs and their distribution in different cities. Multi-source and multi-point early warning systems should be established via combining internet-based big data in the future to conduct effective and early real-time warning. This would create precious time for the early control of COVID-19 outbreaks.  相似文献   
973.
Compared with the nucleic acid amplification test (NATT), the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) rapid antigen self-testing (RAST) has advantages in speed and convenience. However, little is known about people's acceptance and influencing factors for SARS-CoV-2 RAST. A cross-sectional study was conducted from April 21 to 30, 2022 in China. The χ2 test and multivariate logistic regressions were used to identify the influencing factors. The structural equation model was used to test the extended protective motivation theory (PMT) model hypotheses. Among the total of 5107 participants, 62.5% were willing to accept the SARS-CoV-2 RAST. There were significant differences in acceptance among different residences (p < 0.001), educational level (p < 0.001), occupation (p < 0.001), monthly income (p < 0.001), travel frequency (p < 0.05), and feelings about NATT (p < 0.001). Response efficacy (β = 0.05; p = 0.025) and self-efficacy (β = 0.84; p < 0.001) had a positive effect, while response cost showed a negative effect (β = −0.07; p < 0.001). The public's major concerns about SARS-CoV-2 RAST are its reliability, testing method, price, and authority. Overall, a moderate intention to use SARS-CoV-2 RAST was found among the Chinese population. The extended PMT can be used for the prediction of intention to accept the RAST. We need to take measures to increase people's acceptance of SARS-CoV-2 RAST.  相似文献   
974.
975.
~ hepatic lympholna (PHL) is very uncommon, with which most clinicians are not fallliar. We report a case Of p~ hepatic non-Hodgkin's lymphomawhoSe clinical ~stalons were Presented edng withP~ssiVe liVer failure, and the comet diagnosis wascoallrmed by liver biopsy. A review of the lite~re anddiscussion of PHL ~ also Presented.~ ~ ~sPatient A 32-year-old man was abbotted to ourdepallment on APril l, 1999 because of fatigUe, anowhaand loss Of weight for 5 months, feVer for 4 d. The onse…  相似文献   
976.
Clonal analysis of mndne T cells has led to the idenuncation of Z typeS of Th cells, Thl and on. Thl cells,chacterized by secreting interferon-y (Iap-Y), interleukin-2 (IL2) and tumor necrosis factor-5 (TNF-3), involved Principally in cell-mediated ~ity and play acrucial role in defending the host against intracellularPathogens such as a Vallety of yi~es. ThZ cells,secreting IL4, ms, IL-6 and ilo, mostly regulateh~ immune responSe, and may oafs Paxtial PIDtection against extracellula…  相似文献   
977.
通过对19例黄色瘤影像分析,认为其基本表现为颅骨多发性破坏和肺部网粟粒状浸润,5岁以上儿童有颅骨广泛破坏应首先考虑本病,并应常规摄胸片检查。分析认为,X线平片检查是认一病的主要手段,CT和MRI可作为必要补充,MRI对显示垂体腺的细胞微病变具有重要意义。  相似文献   
978.
癌基因c-erbB-2在膀胱移行细胞癌中的扩增   总被引:2,自引:1,他引:1  
赵致广  张莉莉 《医学争鸣》2000,21(4):482-482
0 引言 为探讨癌基因 c- erb B- 2的扩增与膀胱移行细胞癌(TCC)的关系 ,我们以斑点杂交的方法对 40例膀胱 TCC标本中 c- erb B- 2的扩增情况进行了检测 ,以期明确 c- erb B- 2扩增与膀胱 TCC病理分级及患者预后的关系 .1 材料和方法  40例膀胱 TCC患者术后石蜡包埋标本 ,随访 5~ 10 a. 11例正常膀胱粘膜石蜡标本作为对照 . c- erb B-c DNA p CER2 0 4质粒由东京大学提供 ,Bothringer缺口平移 DNA标记试剂盒及 32 P标记 d CTP购于北京福瑞公司 .所有石蜡标本经脱蜡及蛋白酶消化 ,以酚 /氯仿抽提 DNA,乙醇沉淀 .每份样品取…  相似文献   
979.
大黄对脂质过氧化物——丙二醛的影响   总被引:14,自引:0,他引:14  
应用富含脂质过氧化物丙二醛的鼠民中药大黄孵育,观察药物对MDA的影响。结果显示,大黄对MDA呈明显抑制作用,且抑制作用有明显的量效关系。提示临床应用大黄可以抑制MDA生成过多,从而减少轻组织器官损伤,防止痛情恶化。  相似文献   
980.
目的 探讨喉癌手术的疗效,提高喉癌病人的生存质量。方法 53例男性声门型鳞状细胞癌采用垂直前侧位喉大部切除颈前皮瓣和肌筋膜双蒂整复术。术后辅以放疗。结果 53例病人术后吞咽及发音功能基本恢复,拔管率92.5%,3年生存率为82.5%,5年生存率为76.8%。结论 对一侧声带癌向前至声带前联合并累及对侧声带前1/3的病人,采用垂直前侧位喉大部切除颈前皮瓣和肌筋膜双蒂整复是一种有效的术式,在切除肿瘤的  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号